Wow! Now that
does sound a curious situation!
Perhaps you might care to give us an idea of just how old you are, when and how you first started masturbating, whether you have managed to "come" by
any other means, how you came to try the shower head, whether you have had any opportunity to attempt intercourse, and any other related matter that might be relevant? In
particular, some detail what sort of "stroking" you have tried, for how long and how "successful" you felt this was - how "close" you came - to "coming"?
Presumably, your foreskin is much the same as
this fellow mentioned in the thread previous to this?
Perhaps I should point out that "we guys" have not personally suffered from a tight foreskin - but that does not mean we don't know a fair bit about it - Jim in particular has experience and expertise in the process of doing something very similar but far more
difficult - stretching the remains after
circumcision, of foreskin and plain penile shaft skin to "re-form" a foreskin to protect the sensitivity of the glans (penis head) and make intercourse more pleasant for both participants.
You may note from this, why we always take the viewpoint that a circumcision is a really,
really bad way to deal with a foreskin that won't retract.
Getting back to your question, I suspect that you
may not have tried too many variations of "stroking", so we might talk about that if you can clearly describe what you
have tried, but I
would certainly advise the stretching for this and other reasons.